The long term goal of this program is the elucidation of the mechanisms by which peptide and protein hormones regulate their target cells. The system to be investigated is ACTH stimulation of the adrenocortical cell. The main thrust of this research is to isolate and characterize those components of adrenocortical tissue which have been implicated in the process through which ACTH is postulated to regulate corticoid production and to attempt to reconstruct the regulated system. Affinity chromatography as well as standard techniques for protein fractionation will be employed for isolation attempts to adenylate cyclase and phosphoprotein kinase from bovine adrenal cortex. (Biocytin25) ACTH1-25 Amide will be attached to Avidine-Sepharose for the generation of an affinity column which will be employed in isolation studies of ACTH receptors from bovine adrenalcortical plasma membranes. BIBLIOGRAPHIC REFERENCES: F. M. Finn and K. Hofmann, "Preparation of ACTH Sensitive Adrenocortical Membranes", Methods in Receptor Research, ed. by Melvin Blecher, New York: Marcel Deker, Inc. 1976, pp. 37-51. K. Hofmann and Y. Kiso, "An Approach to the Targeted Attachment of Peptides and Proteins to Solid Supports", Proc. Natl. Acad. Sci. U.S., 73, 3516 (1976).